A device for cutting pipes is known from CH 568,117. In this case, a driving motor with a saw blade is advanced by means of an eccentric arrangement of different rings. Subsequently, the driving motor with the saw blade is manually guided around the pipe such that said pipe is cut. The pipe is centered and held in a vise by means of two V-shaped clamping jaws.
When welding a pipe to another pipe by means of an automated orbital welding process, an exact and uniform chamfer must be produced on both pipe ends. Otherwise, the welding process cannot be carried out correctly. This means that the pipe must be chamfered in one additional processing step after it has been cut.
For this purpose, the aforementioned device is equipped with an auxiliary milling cutter. This auxiliary milling cutter is arranged directly adjacent to the saw blade. The driving motor with the saw blade and the auxiliary milling cutter is guided around the stationary pipe once such that the pipe is simultaneously cut and chamfered.
One disadvantage of this device is that an exact chamfer cannot be produced in thin-walled pipes with large diameters because the clamping jaws of the pipe receptacle only accommodate the pipe in pointwise fashion. This means that the thin-walled pipe is clamped in the vise off-center during the clamping process.
Another problem of the aforementioned device is that the auxiliary milling cutter is very susceptible to wear on its front edge, i.e., the outer edge of the auxiliary milling cutter.
The pipe end also must be chamfered if a press fitting with a rubber ring seal is attached. These press fittings are used for connecting two thin-walled pipes of special steel in drinking water installations. In this case, two different chamfers are produced on the pipe ends, i.e., a steep chamfer for attaching and centering the press fitting onto the pipe and a flat chamfer.